Fully Automatic Method for the Visual Acuity Estimation Using OCT Angiographies

[Abstract] In this work we propose the automatic estimation of the visual acuity of patients with retinal vein occlusion using Optical Coherence Tomography by Angiography (OCTA) images. To do this, we first extract the most relevant biomarkers in this imaging modality—area of the foveal avascular zone and vascular densities in different regions of the OCTA image. Then, we use a support vector machine to estimate the visual acuity. We obtained a mean absolute error of 0.1713 between the manual visual acuity measurement and the estimated, being considered satisfactory results.Centro de Investigación de Galicia; ED431G 2019/01Xunta de Galicia; DTS18/00136Ministerio de Ciencia, Innovación y Universidades; RTI2018-095894-B-I0

Valorization of chestnut (Castanea sativa) residues: characterization of different materials and optimization of the acid-hydrolysis of chestnut burrs for the elaboration of culture broths

Four kinds of waste from the industrial processing of chestnuts (Castanea sativa), namely leaves, pruned material and burrs from chestnut tree plus chestnut shells, were characterized to determine their content in polymers and thus their potential use in biorefinery processes. Results revealed that chestnut burrs have the highest polysaccharide content being the most promising for carrying out the subsequent stages of acid hydrolysis. Treatment with diluted sulfuric acid (prehydrolysis) allowed the solubilization of xylose, glucose and arabinose, but also some toxic compounds such as furan derivatives, aliphatic acids and phenolic constituents. Xylose, the main component released in the hemicellulosic hydrolyzates, was maximized by using a 3**(2–0) full factorial design combined with desirability function. At optimum conditions set at 130 °C and 3% (w/v) H 2 SO 4 , this value was 22.6 g L −1 xylose. Three concentrations of activated charcoal (1, 2.5 and 5% w/v) were evaluated to remove certain unwanted byproducts, and it was found that under the highest dosage, 95.27 ± 0.03% of the color was removed with an almost total reduction of furan derivatives, making this liquor an appropriate basis for the development of suitable culture media for lactic acid bacteria. To validate this hypothesis three lactic acid bacteria, namely Lactobacillus plantarum, Lactobacillus pentosus and Lactococcus lactis were positively tested finding lactic acid yields of 0.89, 0.92 and 0.83 g/L·h respectively.Axencia Galega de Innovació

A Novel Automatic Method to Estimate Visual Acuity and Analyze the Retinal Vasculature in Retinal Vein Occlusion Using Swept Source Optical Coherence Tomography Angiography

[Abstract] The assessment of vascular biomarkers and their correlation with visual acuity is one of the most important issues in the diagnosis and follow-up of retinal vein occlusions (RVOs). The high workloads of clinical practice make it necessary to have a fast, objective, and automatic method to analyze image features and correlate them with visual function. The aim of this study is to propose a fully automatic system which is capable of estimating visual acuity (VA) in RVO eyes, based only on information obtained from macular optical coherence tomography angiography (OCTA) images. We also propose an automatic methodology to rapidly measure the foveal avascular zone (FAZ) area and the vascular density (VD) in the superficial and deep capillary plexuses in swept-source OCTA images centered on the fovea. The proposed methodology is validated using a representative sample of 133 visits of 50 RVO patients. Our methodology estimates VA with very high precision and is even more accurate when we integrate depth information, providing a high correlation index of 0.869 with the real VA, which outperforms the correlation index of 0.855 obtained when estimating VA from the data obtained by the semiautomatic existing method. In conclusion, the proposed method is the first computational system able to estimate VA in RVO, with the additional benefits of being automatic, less time-consuming, objective and more accurate. Furthermore, the proposed method is able to integrate depth information, a feature which is lacking in the existing method.Mutua Madrileña; 2017/365

Automatic Visual Acuity Estimation by Means of Computational Vascularity Biomarkers Using Oct Angiographies

[Abstract] Optical Coherence Tomography Angiography (OCTA) constitutes a new non-invasive ophthalmic image modality that allows the precise visualization of the micro-retinal vascularity that is commonly used to analyze the foveal region. Given that there are many systemic and eye diseases that affect the eye fundus and its vascularity, the analysis of that region is crucial to diagnose and estimate the vision loss. The Visual Acuity (VA) is typically measured manually, implying an exhaustive and time-consuming procedure. In this work, we propose a method that exploits the information of the OCTA images to automatically estimate the VA with an accurate error of 0.1713.Instituto de Salud Carlos III; DTS18/00136Ministerio de Economía y Competitividad; DPI2015-69948-RXunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2016-047Ministerio de Ciencia, Innovación y Universidades; RTI2018-095894-B-I0

Statistical power maps for SPM analysis of PET scans

[Abstract] The 10th International Conference on Functional Mapping of the Human Brain, June 13-17, 2004, Budapest, HungaryThis work presents an alternative method for reporting negative results in statistical parametric maps, consisting in estimating the maximum effect size that the test would not detect as significant with a certain probabilityPublicad

Imagen de alta resolución en pequeños animales de laboratorio

La posibilidad de visualizar y cuantificar la función de un determinado órgano en animales de laboratorio es una herramienta científica de gran importancia en el estudio de modelos de enfermedades humanas, en el descubrimiento y desarrollo de nuevos medicamentos y en la caracterización del fenotipo de animales transgénicos y noqueados. La tomografía por emisión de positrones (PET) y la imagen proyectiva de radiofármacos marcados con emisores de positrones proporcionan una herramienta genérica y no invasiva para la investigación científica en los casos anteriormente expuestos. En este trabajo se describe un sistema mutimodal PET/CT basado en cámaras de coincidencia y detectores de estado sólido para los rayos X, diseñado para adquirir tanto imágenes tomográficas como de proyección con alta resolución temporal, con capacidad para visualizar ratas y ratones, estos últimos en cuerpo completo en un solo campo de visión.Publicad

Effects of morphine self-administration on brain glucose metabolism in rats

Abstract of: AMI Annual Conference 2006, March 25-29Chronic exposure to opiates has been shown to influence neural activity in brain regions related to the rewarding process. It also induces neuroadaptations which lead to addiction. We have found in previous works that morphine self-administration produces neuroadaptative changes in brain areas of Fischer-344 rats. The aim of this study is to examine the effect of chronic self-administration of morphine on cerebral glucose metabolismPublicad